Clutches with a fluid and cam operated pressure modulating valve

ABSTRACT

A clutch engaging and trolling valve for a marine gear transmission which transmission has both a forward and reverse clutch. The control valve permits trolling of the vessel in either the forward or reverse directions and also insures smooth and shock-free engagement of either the forward or reverse clutch. A single operating lever controlls both the clutch engaging &#39;&#39;&#39;&#39;controlled rate of pressure rise&#39;&#39;&#39;&#39; mode and the trolling mode.

United States Patent [191 Arnold CLUTCHES WITH A FLUID AND CAM OPERATED PRESSURE MODULATING VALVE [75] Inventor: Bruce C. Arnold, Racine, Wis.

[73] Assignee: Twin Discs Incorporated, Racine,

Wis.

[22] Filed: Sept. 7, 11973 [21] Appl. No.: 395,200

Primary Examiner-Benjamin W. Wyche Attorney, Agent, or Firm-James E Nilles [57] ABSTRACT A clutch engaging and trolling valve for a marine gear transmission which transmission has both a forward CONTROLLED RATE or PRESSURE RISE MODE PRESSU [52] 192/ 192/109 kg K 3; and reverse clutch. The control valve permits trolling of the vessel in either the forward or reverse directions 22 g and also insures smooth and shock-free engagement of e are either the forward or reverse clutch. A single operating lever controlls both the clutch engaging ,con- [56] Referencs Cited trolled rate of pressure rise" mode and the trolling mode. UNITED STATES PATENTS 2,775,328 12/1956 Yokel 192/85 R Claims, Drawing Figures l D 22 58 l I Us l R ,89 126 LUBE& CLUTCH I ii: i

COOLING I SSV BSV N 1 I x P I A02 F F F CLUTCH i 1 44 R I l i f l l l RE REGULATOR VALVE 3.823.801 sum 1 or 9 PATENTEB JUL 1 61974 1 I\) F 0% from f 9 2. x T1 3 PM I 7 m? L w o: 2 5 5 i A 5 @m mm m E 1 i H r i 1L2)? mm 9 pm 3 wm o: a 5 Now H; I AM l/ -1 mm E Q N T 1. m 3 8 Crt 8 m mNF l\\ |l\ (I mm AIF EVE PATENTEDJUU sum 80F 9 3'823 126 LUBE& CLUTCH COOLING HM CLUTCH LUBE & CLUTCH COOLING 1 FIG. 16

PATENTED 51974 SHE 9 3.823.801

HIGH CLUTCH PRESSURE VS TIME 300 L I 143 144 141 E 1/ a 200 I a w M I O. z E 100 z 3 140 LLJ (z I TIME, SECONDS FIG. 17 DETENT FULLY ENGAGED- TROLLING PRESSURE Vs EGIE QE 'E P'STON REGULATOR LEvER POSITION DETENT STAR S v To ENGAGE L 9o I v v 8O v I I I U') 01 ma TROLL 0ETENT- a so T mv Ex 7 0.. I I g 40 T- 30 I,

0 10 3o so W Y 1 ANGULAR LOCATION OF TROLLING LEVER, DEGREES TROLLING PRESSURE E BACKGROUND OF THE INVENTION This invention pertains to a hydraulic control mechanism for marine gear transmissions of the type having a forward andreverse clutch and in which the trolling function is to be provided in both the forward and reverse directions of the vessel.

This invention isin the nature of an improvement over two patents which have been assigned to an assignee common with the present invention, the first of which is U.S. Pat. No. 3,042,156 issued July 3, 1962 to E. C. Yokel and entitled Fluid Actuated Friction Clutch. That patent provided a control valve for the selection of the forward or reverse clutch to be engaged and also for regulation of hydraulic pressure during and after clutch engagement. While that valve did insure a low hydraulic pressure to initiate clutch engagement without shock and then build-up pressure over a predetermined time in both forward or reverse directions it did not provide for manually adjusted low hydraulic apply pressure which is required for a trolling function. The other patent is U.S. Pat. No. 2,775,328 issued Dec. 25, 2957 to E. C. Yoke] and was entitled Slip Operating Clutch and Cooling Means Therefor. That patent utilized a means to direct regulated high pressure fluid to fully engage a selected clutch and in addition, had a high pressure regulating means, and means to bleed actuating oil from the engaged forward clutch to permit its slipping for modulation of the output speed. That particular valve could only provide the trolling function to either the forward or reverse clutch whose pressure line it intercepted.

SUMMARY OF THE PRESENT INVENTION The present invention provides a valve arrangement for a trolling function in either the forward or reverse directions. A single regulating valve and a single operating lever are used to provide either a controlled rate of rise of pressure for either the forward or reverse clutch, during clutch engagement, and they also provide, a trolling function for either the forward or reverse clutch. The regulator valve spring can be controlled either hydraulically by the controlled rate of pressure rise piston follower or can be controlled mechanically under the manual control of the operator when in the trolling position. The valve thus provides a single pressure regulator which is controlled by the manual lever to cause reduced clutch pressure for trolling. A dented position on this lever beyond the maximum trolling position, brings into play the controlled rate of rise pressure to engage the selection clutch in such a manner so as to reduce clutch engaging shock. The pressure rise in the clutch is triggered by a clutch selection lever,'the selector spool and selector lever also being components of the valve assembly and which directs pressure fluid to move the regulator spring follower. Thus both the trolling pressure and initial clutch engagement pressure are under control of a single pressure valve.

These and other objects and advantages of the present invention will appear hereinafter as this disclosure progresses, reference being had to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a rear, elevational end view of a transmission embodyingthe present invention, certain parts being shown as broken away, in section, or removed for the sake of clarity in the drawings;

FIG. la is a sectional view taken on line la-la of FIG. 1;

FIG. 2 is a side view in section, of the transmission shown in FIG. 1, the view being taken generally along the line 22 in FIG. 1;

FIG. 3 is a side elevational view of the transmission shown in FIGS. 1 and 2, but taken from the side opposite that of FIG. 2, certain parts being shown as broken away for clarity; the valve TV being in the trolling mode;

FIG. 4 is a vertical sectional view taken along the line 4-4 in FIG. 5, and again showing the valve TV in trolling position;

FIG. 5 is a vertical, sectional view taken generally along the line 55 in FIG. 1, certain parts being shown as broken away or removed for the sake of clarity and showing the valve TV in non-trolling, i.e., rate of rise position;

FIG. 6 is a vertical elevational view taken along the line 66 in FIG. 5;

' FIG. 7 is a horizontal, cross-sectional view taken along the line 77 in FIG. 5;

FIG. 8 is a vertical view taken along the line 8-8 in FIG. 3, the view beingpartially in cross section;

FIG. 9 is a vertical view taken along the line 9-9 in FIGS. 3 or 5;

FIG. 10 is a vertical sectional view taken along the line 10-10 in FIG. 3 and when the valve is rotated to a trolling position;

FIG. 11 is a vertical sectional view similar to FIG. 10, but taken along the line 11-11 in FIG. 5 when the valve TV is in the rate of rise position;

FIG. 11a is a view taken along line Ila-11a in FIG. 5;

FIG. 12 is a view taken along the line 12-12 in FIG. 5, but on an enlarged scale;

FIG. 13 is a sectional view taken along the line 13-13 in FIG. 12;

FIG. 14 is a perspective, partially exploded view of certain of the parts shown in some of the other figures, certain parts also being shown as broken away for clarity;

FIG. 15 is a hydraulic schematic diagram of the transmission in accordance with the invention;

FIG. 16 is another schematic showing of the hydraulic circuit of the transmission;

FIG. 17 is a graph showing the rate of rise of the clutch pressure possible with the present invention; and

FIG. 18 is a graph showing the angular position of the trolling lever plotted against the regulator pressure and showing the range of pressure during the trolling function.

DESCRIPTION OF A PREFERRED EMBODIMENT The general organization ofthe transmission with which the present invention is used includes an input gear 1 (FIG. 2) which is attached to and driven by a power source such as by a flywheel 2 of an internal combustion engine (not shown). The input gear is fixed 3 to and rotatably drives input shaft 3 to which a gear 4 is fixed.

CLUTCHES A forward clutch F is of the interleavedfriction plate type and is itself of Conventional character. The forward clutch F includes a drum member 5 having a gear -6 formed integrally around its periphery for constant mesh with and for being driven by the gear 4. The drum 5 and its gear 6 are fixed to the forward clutch shaft 8 for being driven therewith by the input gear 4. A clutch hub member 10 is journalled on the shaft 8 and has a gear 12 formed integrally therewith. Interleaved friction clutch plates 14 and 16 are axially splined, respectively, to the interior ofclutch drum 5 and a peripheral portion of the clutch hub 10, in the known manner. A clutch actuating chamber 18 is formed between the gear 6 and an axially shiftable clutch actuating piston 20 so that when pressure fluid is admitted via the drilled passageway 22 in shaft 8 to the clutch actuating chamber 18, the piston 20 is urged against the plates for clamp-up against the back-up ring 24 of the drum 5, thereby engaging the clutch.

As will appear, the amount of pressure fluid directed to chamber 18 may be varied thereby varying'the degree of clutch clamp-up. That is to say, the clutch may be made to slip in any amount, as well as being made to fully clamp-up, and this is'referred to as a clutch of the modulatable type.

When the clutch F is engaged, power is transmitted from the input shaft 3, through gear 4, gear 6, and its drum 5, the interleaved clutch plates 14 and 16, the clutch hub 10 and its gear 12, and then to the output gear 26 on the output shaft 28.

Shafts 3, 8, and 28 are suitably journalled on antifriction bearing assemblies as clearly shown, and which are supported in the housing H of the transmission.

As shown in FIGS. 1, l4 and 15, a reverse clutch R is also provided and is similar in construction to the forward clutch F, and as it is also of conventional character, a detailed description of it is deemed to be neither necessary nor desirable. It is believed sufficient to say that the reverse clutch R has an integrally formed gear 32 (FIGS. I and 14) around the periphery of its drum 33, which gear is in constant mesh with the gear 6 of the forward clutch F. Furthermore, the reverse clutch includes an output gear 34 which corresponds to the gear 12 of the forward clutch, and which gear 34 is journalled on the shaft 36 and is rotatably driven when the reverse clutch is engaged. As shown in FIG. 1, the gear 60f the forward clutch and the gear 32 of the reverse clutch are in constant mesh with each other. In addition, the output gears 12 and 34 of the forward and reverse clutches, respectively, are in constant mesh withv the large gear 26 (FIG. 1).

When power is desired to be transmitted from the input shaft 3 to drive the output shaft 28 in the reverse direction, that is in the direction opposite to that in which the forward clutch rotates shaft 28, the forward clutch F is disengaged and the reverse clutch R is engaged. Consequently, power flows from the flywheel 1 through gear 4, gear 6,, gear 32 of the reverse clutch to thereby drive the output gear 34 and consequently, the

output gear 26 and shaft 28 fixed thereto.

CLUTCH SELECTION To engage the forward clutch F, pressure fluid is admitted to the clutch actuating passage 22 (FIGS. 2, 4, 7 and 14) in shaft 8 of the forward clutch from the annular groove 23 around shaft 22, and passage 42 (FIGS. 2 and 4) in the valve body B. Pressure fluid is directed to the passage 42 from a central bore 43 (FIGS. 4, 5 and 7) of a direction selector spool 55, to be described. This pressure fluid comes to the spool via conduit means 45 (FIG. 4) from a pressure source, such as a fluid pump P, via a fitting 45a (FIGS. 3 and 4) and ports 47 in spool 55.

The reverse clutch is similar to the forward clutch and is similarly supplied with pressure fluid. For example, pressure fluid is directed to the reverse clutch through the axial passage 44 (FIG. 14) in its shaft 36 and from thefannular groove 46 formed around the shaft 36, which groove 46 receives the pressure fluid from passage 48 in the pump mount 48a, (FIG. 1) jumper conduit 49, and the passage 50- in the valve bodyB. As shown also in FIG. 7, passage 50 is in fluid communication with a cored passageway 51 (also FIG. 9), passage 52, and passage 53, which is alignable with a port 54 in a spool 55 and which leads to the central bore 43 of the direction selector valvespool 55.

When the valve spool 55 is turned by a selection lever 58, so that its passage 54 communicates with passage 53, fluid pressure is admitted to the reverse clutch R. On the other hand, when the spool 55 is turned in the opposite direction, thepassage 54 communicates with passage 42 to feed pressure fluid to the forward clutch causing its engagement, as previously described. Thereby, the direction selector spool 55 of the direction selector valve DS can be turned by its lever 58 to one position or the other so as to selectively engage either the forward or reverse clutch which consequently drives a vessel (not shown), in which the transmission is used, in the forward or reverse direction.

PRESSURE REGULATOR VALVE WITH A CONTROLLED RATE OF PRESSURE RISE A pressure regulator valve with a controlled rate of pressure rise RR will be described which regulates the rate at which the pressure in either the forward or reverse clutch builds up to engage that clutch. In other words, this valve RR determines the rate or speed at which the clutches are engaged. However, this rate of rise valve does not function until the direction selector valve DS has first selected either the forward or reverse direction as mentioned. When the direction selection has been made, the rate of rise function of the valve to be described then comes into play as follows.

Referring in particular to FIGS. 4, 5 and 14, the rate of pressure rise valve RR includes a high pressure regulating piston 60 which has a stem portion 61 axially slideable in the central bore 43 of the direction selector spool 55. A hollow pressure rise piston cup 62 is axially slidable in a bore 63 in the valve body, and spring means 64 is located in this piston cup 62 and bears against the underside of the pressure regulating piston 60. The spring tends to urge the piston cup 62 in a downward direction against'a cam surface 66, to be described, and urges the regulating piston 60 upwardly, against the fluid pressure in bore 43 acting on the upper end of stem portion 61. The fluid pressure which is always present in bore 43 tends to urge the piston 60 downwardly. Radial ports 67 are located in spool 55 and extend from chamber 43 to a peripheral groove 68 in the spool.

rected from passage 69, through cored passage 69b;

through a port 115 communicating with the bore 110 (FIG. 8) which houses the spool shuttle valve SSV, to be described, and which valve provides a priority flow of lubricating fluid to either the forward or reverse clutch, whichever is being engaged, as will be described later.

TROLLING VALVE TV Controlled Rate of Pressure Rise position As shown in FIGS. 1, 5 and 11, the trolling valve TV is in a controlled rate-of-pressure rise position in which the pressure regulator valve RR with controlled rate of pressure rise is operative to control the speed or rate of clutch engagement. In this controlled rate of pressure rise position of valve TV, the spring loaded latch 72 engages a detent 73 in the member 74 which is rotatable in bore 75. Consequently, this is also referred to as the detent" position and is the limit of rotation of member 74 in one direction.

The trolling valve TV has a right angular fluid passage 76 (FIGS. 5 and 6) which leads from a valve body passage 77, when in alignment therewith, to a cavity 78 located around the eccentric cam portion 66 of the trolling valve.

As shown in FIG. 11, when the rotatable member 74 is in the position shown, the passage 76 is aligned with the pressure line 77, and this permits pressure fluid to flow from a combined orifice and check valve assembly OC (FIGS. 5, 7, l2, l3 & through the passage 77 to pressurize the cavity 78 and, more particularly, to act on the underside of the piston cup 62, urging it upwardly against the bias of the spring 64. That is to say, the force of spring 64 can now be adjusted hydraulically. This controlled rate-of-pressure rise position is the maximum clutch pressure position, the member 74 is in the detent position and the length of the spring 64 is reduced, that is, the spring is compressed and its force at a maximum. Thus, with the lever 70 in the de tent position shown in FIG. 5, the passage 76 in the rotatable member 74 of the trolling valve is in communication with clutch engaging pressure fluid and conducts it through the orifice 104 of valve CC (to be described) and into the eccentric cam cavity 78 and thus hydraulically advances the pressure rise piston cup 62 at a rate which is a function of the orifice size, until the piston cup 62 abuts shoulder 63a. The rate of rise of clutch pressure is shown by line 141 in FIG. 17, to be referred to later. The hydraulic advance of the piston cup 62 thus permits an increase in the clutch engaging pressure from a relatively low value, as at point 140 in FIG.

sulting in an increase in clutch 17, which is still above the trolling pressure and upto the maximum pressure (point 143, FIG. 17) which is required to fully engage the clutch.

Trolling Position As shown in FIG. 10, when the valve member 74 is rotated from the detent position and to the position shown (also FIGS. 3 and 4), a trolling mode is presented which vents the cavity 78 via port 79a and a recess 79 in the periphery of member 74, to a sump pas- I sage 80 (also FIG. 5) and consequently to the sump S. Sump passage 80 also vents other spaces as shown in the drawings.

In the trolling mode (FIGS. 3, 4 and 10) the length of the spring 64 is under the manual controlof the operator by means of the lever 70, and the spring is working at its longer length as compared to its length in the controlled rate-of-pressure rise mode. By moving the lever 70, the operator rotates the eccentric cam 66 and thereby shifts the piston cup 62 to vary the length of the regulator spring 64.

When the trolling valve TV is in the slowest trolling position, the end 81 of the flat, chordal. surface 82 (FIGS. 6, 11a and 14) formed in member 74 abuts against a stop 82a, and prevents further rotation. of member 74. The amount of rotation from the detent position to the position where end 81 abuts against stop 82a is about 79. When end 81 hits stop 82a, this presents the'longest spring length and results in the least force on theregulator piston cup 62 and consequently the least clutch pressure. That is to say, it provides maximum clutch slip and lowest speeds for trolling. As the lever 70 is moved toward the detent position, the length of the spring 64 becomes less, that'is it is compressed, and thereby the spring force isincreased, repressure and trolling speed.

BALL SHUTTLE VALVE When one orthe other of the clutches F or R is engaged, a ball shuttle valve BSV (FIGS. 1, 7, 14,15 and 16) directs a portion of clutch engaging pressure through combined orifice and check valve CC to be described, through the passage 77 and through passage 76 and into previously described cavity 78. As will further-' more appear, clutch engaging pressure also acts on a spool shuttle valve SSV (FIGS. 1, 8, l4, l5 and 16) to give priority of pressure fluid flow (which is discharged by the regulator valve RR) to that particular clutch F or R which is selected to engagement, thereby acting to cool the plates of that particular clutch which is being engaged.

More specifically, the ball shuttle valve BSV (FIGS! 1, 7,14, 15, and l6) includes a stationary spool member 83 having a tubular end portion84. Ports 85 are formed through the tubular portion 84 while other ports 86 are formed in the opposite end of the spool 83. A shiftablve valve element in the form of a ball 88 is located in the tubular end 84 and (as-shown in FIGS. 1 and 7) can abut against a seat 87 to block fluid flow from a passage 89 and cause high pressure fluid to flow through a passage 90 and to the combined orifice and check valve assembly DC to be referred to.

When the forward clutch F is being engaged and high pressure fluid is in passage 42 (FIG. 1 and 7) to feed the clutch F via passage 22, some of this high pressure fluid also flows through passage 89 and 90 and through the orifice 104 of the combined orifice and check valve OC to passage 77 (FIGS. and 7) which, as previously described, communicates with the right angular passage 76 in the trolling valve member 74, and consequently conducts the pressure fluid to the cavity 78 at the bottom of the pressure rise piston cup 62. Thus, a portion of the pressure fluid which is being directed to the forward clutch F is also directed via orifice 104 to the cavity 78 beneath the pressure rise piston.'

Similarly, when the selector spool 55 is turned to conduct pressure fluid to passages 53, 52, 51 and 49 (FIG. 7) and consequently to the reverse clutch R, as previously described, a certain portion of this high pressure fluid also flows through passageway 102 (FIG. 7), unseating the check ball 88 and thereby conducting the high pressure fluid through the orifice 104 of the combined orifice and check valve OC, passages 77 and 76 to the cavity 78 beneath the pressure rise piston cup 62.

In summary, when either the forward or reverse clutch is pressurized, a certain amount of pressure fluid is also conducted to the bottom of the pressure rise piston cup 62. I

' The combined orifice and check valve 0C, previously referred to, is shown schematically in FIG. 15 and is also shown in greater detail in FIGS. 12 and 13. This combined valve in itself is conventional and is shown I SPOOL SHUTTLE VALVE The spool shuttle valve SSV gives priority of pressure fluid flow (which has been discharged by the pressure regulating,.rate of rise valve RR) to either the forward or reverse clutch which has been selected for engagement, to thereby cool that particular clutch. This spool shuttle valve (FIGS. 1, 8,- 14 and 15) includes an axially shiftable spool 111 having a central passage 112 which, as previously explained, permits flow of fluid pressure from pressure chamber 43 (FIGS. 4 and 5) through passages 69, 69b and port 115 and into the annular recess 116 (FIG. 8) on the periphery of spool 111. From recess 116, the pressure fluid is available to go to either the forward or reverse clutch plates depending on the axial position of the spool 111. The axial position of the spool 111 is determined by the admission of pilot pres sure at either end of the spool, that is, through port 117 (FIGS. 7 and 8) if the forward clutch is engaged'and is to be cooled, or through port 122 (FIGS. 8 and 9) ifthe reverse clutch is engaged and isto be cooled. I

More specifically, when the forward clutch F is engaged, high pressure fluid flows through collector passage 46 (FIGS. 1A and 14), passage-113 (FIGS. 1, 7 and 8) and passage 117 to the lower end (FIG. 8) of the spool 111 to axially shift the spool so that port 115,- which has received'high pressure fluid, as previously described, is in communication with port 120 (FIGS. 7, 8 and 9) leading via passage 123 to passage 126 (FIG.

. 2) and to the clutch plates and bearings of clutch F.

When thereverse clutch R is engaged, it then gets the priority flow for lubrication, as follows. Pressure fluid is directed via passages 53, 52 and 51 (FIGS. 7 and 9) through passage 122 (FIGS. 9 and 8) and then through the radial passage 125 in spool 111 and into the center of spool 11] to shift it axially downwardly (FIG. 8). Pressure fluid coming in port 115 as described then can flow via annular groove 116 in the spool and through port 118 (FIGS. 8 and 4) through cross-over tube 124 (FIGS. 1, la, 4 and 8) cored passage 127, annular spool 46 and axial passage 44 in shaft 36 to cool the clutch R plates and bearings, as also indicated in FIG. 15.

This priority of flow of lubricating fluid to the engaged clutch is operative in both rate-of-rise mode, in the trolling mode or in neutral-because pressure fluid is always available in chamber 43 of spool 55.

OPERATION Assume the lever is in the detent position shown in FIG. 5. Pressure fluid from the pump is available at all times in chamber 43. When it is desired to select either forward or reverse clutch, the spool 55 is turned by handle 58 which causes pressurefluid to be directed out of port 54 and to either of the clutch actuating chambers of either the forward or reverseclutch. For example, if it is desired to operate the forward clutch, fluid pressure is directed via passage 42, passage 22 and into the clutch actuating chamber 18 to thereby initiate clutch clamp-up. Whenever either of the forward or reverse clutches is thus selected, a certain amount of pressure fluid is also directed through ball shuttle valve BSV, through the orifice and check valve OC, passage 77, and the aligned passage 76 to the cavity 78 below the piston cup 62. Thus, the clutch actuating chamber- 18 builds up pressure to commence engagement of the clutch, and as this is occurring pressure through the orifice 104 enters cavity 78 and also builds up in cavity 78.

Pressure in cavity 78 becomes approximately equal to that in chamber 42, but as the area of the top of the piston stem 61 is less than the area on the bottom side of the piston 60, the cup 62 through the spring 64 urges the piston 60 upwardly to close the ports 67. The upper end of the piston cup 62 abuts against the shoulder 63a. As the clutch then fully clamps up, the pressure rises in chamber 43 and pushes the piston 60 downwardly against the resiliency of the spring. The top of the piston stem 61 moves downwardly to open passages 67 to the pressure in chamber 43. This pressure then passes through passage 69 and to port of the spool shuttle valve SSV. The spool shuttle valve in turn directs a certain amount of pressure fluid to the clutch plates between either the forward or reverse clutch, that is via passage 126 or passage 127, respectively, to therebycool the plates and bearings of that particular clutch which had been selected for engagement. Thus a priority of lubricating pressure fluid is directed to the clutch selected and is effective to cool the clutch as soon as it is engaged.

This is the rate of rise position of the valve mechamsm. I When it is desired to utilize the trolling mode of the present invention, the lever 70 is moved out of the detent position and can be swung through a certain trolling range. That is to say, when the clutch is moved off the detent position, the passage 76 is no longer in alignment with passage 77, and instead the cavity 78 is vented to the sump via the passage 79. The piston cup 62 bears against the cam 66 of the trolling lever and consequently the force of the spring 64 is under themfluence of the lever-70. In this manner, the pressure of either the forward or reverse clutch can be varied through an arcuate swinging movement of about 79 degrees of the trolling lever 70. 7

As shown in FIG. 17, the clutch pressure builds up from its initial engagement at point 139, and builds up rather rapidly to point 140 just before the piston 61 opens chamber'43 to passage 67. When the piston 60 thus opens the chamber 43, the pressure rise in the clutches is then along line 141 and it will be noted that this is a gradual and smooth rate of rise of clutch pressure, When point 143 is reached, the clutch is fully clamped up, operating along the clutch pressure line 144 which is generally constant.

As shown in FIG. 18, the trolling lever 70 is actuated through swinging of approximately 79 degrees, from a minimum trolling pressure indicated at 146 to a maximum trolling pressure indicated generally at 148 adjacent the detent position. Thus, an accurate trolling speed is possible with either the forward or reverse clutches.

With the present invention, a single pressure regulator valve is utilized to control the rate of rise of fluid pressure build-up in either the forward or reverse clutches.

Secondly, the same pressure regulator valve controls the clutch trolling pressure and. thus the speed. Thus, a single lever 70 is'utilized to provide either the controlled rate of pressure rise or trolling modes.

A priority of lubricating fluid flow to the clutch selected is automatically provided. The size of the orifice and check valve may be varied to control the rate at which the pressure in the clutch builds up, that is one orifice and check valve having a different size'oriflce.

I claim:

1. A marine gear transmission of the type having both forward and reverse, hydraulically actuated, modulatable friction clutches which are selectively engagable to drive a vessel in the forward or reverse directions respectively, said transmission having hydraulic control means for said clutches and comprising; a direction selector valve for directing pressure fluid selectively-to either said forward or reverse clutch for engagement thereof, a pressure regulator valve with a controlled rate or pressure rise mode for regulating the fluid pressure admitted to said clutches for engagement of said clutches, said pressure regulator valve comprising a shiftable piston operatively associated with said selective valve to regulate the pressure fluid delivered by said selector valve to said clutches, a spring loaded follower for resiliently urging the piston to a high pressure position, a trolling valve for engagement with said follower and shiftable between (a) a controlled rate-ofpressure rise position whereby said follower is shifted to a maximum pressure position and (b) a trolling position for a range of movement for shifting said follower over a range of lower pressure for trolling, and an orifice and check valve means connected in fluid communication with and between said selector valve and said trolling valve for admitting pressure fluid to said trolling valve, whereby when said trolling valve is in said controlled rate-ofpressure rise position, then pressure fluid can flow to said follower to thereby permit said piston to be hydraulically adjusted and consequently regulate the rate of rise of pressure'in said clutches, and when said trolling valve is in said trolling position then pressure fluid flow is blocked to said follower and the latter is manually adjusted by movement of said trolling,

valve through said range of movement.

2. The transmission set forth in claim 1 including a shuttle'valve for directing lubricating fluid between the clutch plates of either the forward or reverse clutch which has been selected for operation to thereby cool said clutch, said shuttle valve being in fluid communication with said selector valve and receiving pressure fluid therefrom, whereby when said selector valve is shifted to convey pressure fluid to either the forward or reverse clutch, said shuttle valve also receives pressure fluid from said selector valve and directs it either to the forward or reverse clutch which has been selected for engagement to thereby cool the latter.

3. The transmission set forth in claim 1 further characterized in that said trolling valve has an eccentric cam portion which can abut against said follower and shift the position of the spring loaded follower relative to said piston to thereby vary the force on said piston which urges the latter to a maximum-pressure position.

4. A marine gear transmission of the type having both forward and reverse, hydraulically actuated, modulatable friction plate clutches which are selectively engagable to drive a vessel in the forward or reverse directions respectively, said transmission having hydraulic control meansfor said clutches and comprising; a direction selector valve for directing pressure fluid selectively to either said forward or reverse clutch for engagement thereof, pressure regulator valve with a controlled rate of pressure rise mode for regulating the fluid pressure admitted to said clutches for engagement of said clutches, said pressure regulator valve comprising a shiftable piston operatively associated with said selective valve to regulate the pressure fluid delivered by said selector valve to said clutches, said pressure regulator valve also having a controlled rate-of-pressure rise portion comprising a shiftable piston follower with a spring bearing against said piston, said spring being located between said follower and said piston, said follower and spring resilientlyv urging the piston to a high pressure position, a trolling valve having an eccentric cam for engagement with said follower and shiftable between (a) a controlled'rate-of-pressure rise position whereby said follower is shifted to a'maximum pressure position and (b) a trolling position for a range of movement for shifting said follower over a range of lower pressure for trolling, and anorifice and check valve means connected in fluid communication with, and between said selector valve and said trolling valve for admitting pressure fluid to said trolling valve, whereby when said trolling valve is in said controlled rate-ofpressure rise positiq then pressure fluid can flow to said follower to thereby permit said piston to be bydraulically adjusted and consequently regulate the controlled rate of rise of pressure'in said clutches, and when said trollingvalve is in said trolling position then pressure fluid flow is blocked to said follower and the latter is manually adjusted by movement of said trolling valve through said range of movement; a priority flow lubricating valve for directing lubricating fluid between the clutch plates of either the forwardor reverse clutch whichhas been selected for operation. to thereby cool said clutch, said lubricating valve being in fluid communication with said selector valve and receiving pressure fluid therefrom, whereby when said selector valve is shifted'to convey pressure fluidto either the forward or reverse clutch, said lubricating valve also receives pressure fluid from said selectorvalve and directs it either to the forward or reverse clutch which has been selected for engagement to thereby cool the latter.

5. A marine gear transmission of the type having both forward and reverse, hydraulically actuated, modulatable friction clutches which are selectively engageable to drive a vessel in the forward or reverse directions respectively, said transmission having hydraulic control 7 trolling valve for engagement with said regulator means and shiftable between (a) a controlled rate-of-pressure rise position whereby said regulator means is shifted to a maximum pressure position and (b) atrolling position for a range of movement for shifting said regulator means over a range of lower pressure for trolling, and an orifice and check valve means connected in fluid communication with and between said selector valve and said trolling valve for admitting pressure fluid to said trolling valve, whereby when said trolling valve is in said controlled rate-of-pressure rise position, then pressure fluid can flow to said regulator means to hydraulically adjust said regulator means and consequently control the rate of rise of pressure in said clutches, and when said trolling valve is in said trolling position then pressure fluid flow is blocked to controlled rate of pressure rise means and the latter is manually adjusted by movement of said trolling valve through said range of movement. 

1. A marine gear transmission of the type having both forward and reverse, hydraulically actuated, modulatable friction clutches which are selectively engagable to drive a vessel in the forward or reverse directions respectively, said transmission having hydraulic control means for said clutches and comprising; a direction selector valve for directing pressure fluid selectively to either said forward or reverse clutch for engagement thereof, a pressure regulator valve with a controlled rate or pressure rise mode for regulating the fluid pressure admitted to said clutches for engagement of said clutches, said pressure regulator valve comprising a shiftable piston operatively associated with said selective valve to regulate the pressure fluid delivered by said selector valve to said clutches, a spring loaded follower for resiliently urging the piston to a high pressure position, a trolling valve for engagement with said follower and shiftable between (a) a controlled rate-of-pressure rise position whereby said follower is shifted to a maximum pressure position and (b) a trolling position for a range of movement for shifting said follower over a range of lower pressure for trolling, and an orifice and check valve means connected in fluid communication with and between said selector valve and said trolling valve for admitting pressure fluid to said trolling valve, whereby when said trolling valve is in said controlled rate-of- pressure rise position, then pressure fluid can flow to said follower to thereby permit said piston to be hydraulically adjusted and consequently regulate the rate of rise of pressure in said clutches, and when said trolling valve is in said trolling position then pressure fluid flow is blocked to said follower and the latter is manually adjusted by movement of said trolling valve through said range of movement.
 2. The transmission set forth in claim 1 including a shuttle valve for directing lubricating fluid between the clutch plates of either the forward or reverse clutch which has been selected for operation to thereby cool said clutch, said shuttle valve being in fluid communication with said selector valve and receiving pressure fluid therefrom, whereby when said selector valve is shifted to convey pressure fluid to either the forward or reverse clutch, said shuttle valve also receives pressure fluid from said selector valve and directs it either to the forward or reverse clutch which has been selected for engagement to thereby cool the latter.
 3. The transmission set forth in claim 1 further characterized in that said trolling valve has an eccentric cam portion which can abut agaInst said follower and shift the position of the spring loaded follower relative to said piston to thereby vary the force on said piston which urges the latter to a maximum pressure position.
 4. A marine gear transmission of the type having both forward and reverse, hydraulically actuated, modulatable friction plate clutches which are selectively engagable to drive a vessel in the forward or reverse directions respectively, said transmission having hydraulic control means for said clutches and comprising; a direction selector valve for directing pressure fluid selectively to either said forward or reverse clutch for engagement thereof, pressure regulator valve with a controlled rate of pressure rise mode for regulating the fluid pressure admitted to said clutches for engagement of said clutches, said pressure regulator valve comprising a shiftable piston operatively associated with said selective valve to regulate the pressure fluid delivered by said selector valve to said clutches, said pressure regulator valve also having a controlled rate-of-pressure rise portion comprising a shiftable piston follower with a spring bearing against said piston, said spring being located between said follower and said piston, said follower and spring resiliently urging the piston to a high pressure position, a trolling valve having an eccentric cam for engagement with said follower and shiftable between (a) a controlled rate-of-pressure rise position whereby said follower is shifted to a maximum pressure position and (b) a trolling position for a range of movement for shifting said follower over a range of lower pressure for trolling, and an orifice and check valve means connected in fluid communication with and between said selector valve and said trolling valve for admitting pressure fluid to said trolling valve, whereby when said trolling valve is in said controlled rate-of-pressure rise position, then pressure fluid can flow to said follower to thereby permit said piston to be hydraulically adjusted and consequently regulate the controlled rate of rise of pressure in said clutches, and when said trolling valve is in said trolling position then pressure fluid flow is blocked to said follower and the latter is manually adjusted by movement of said trolling valve through said range of movement; a priority flow lubricating valve for directing lubricating fluid between the clutch plates of either the forward or reverse clutch which has been selected for operation to thereby cool said clutch, said lubricating valve being in fluid communication with said selector valve and receiving pressure fluid therefrom, whereby when said selector valve is shifted to convey pressure fluid to either the forward or reverse clutch, said lubricating valve also receives pressure fluid from said selector valve and directs it either to the forward or reverse clutch which has been selected for engagement to thereby cool the latter.
 5. A marine gear transmission of the type having both forward and reverse, hydraulically actuated, modulatable friction clutches which are selectively engageable to drive a vessel in the forward or reverse directions respectively, said transmission having hydraulic control means for said clutches and comprising; a direction selector valve for directing pressure fluid selectively to either said forward or reverse clutch for engagement thereof, a pressure controlled rate-of-pressure rise valve for regulating the fluid pressure admitted to said clutches for engagement of said clutches, said rate of rise valve having a resiliently biased regulator means including a shiftable piston associated with said selective valve to regulate the pressure fluid delivered by said selector valve to said clutches, said regulator means urging the piston to a high pressure position, a trolling valve for engagement with said regulator means and shiftable between (a) a controlled rate-of-pressure rise position whereby said regulator means is shifted to a maximum pressure position and (b) a trolling position for a range of movement for shifting said regulator means over a range of lower pressure for trolling, and an orifice and check valve means connected in fluid communication with and between said selector valve and said trolling valve for admitting pressure fluid to said trolling valve, whereby when said trolling valve is in said controlled rate-of-pressure rise position, then pressure fluid can flow to said regulator means to hydraulically adjust said regulator means and consequently control the rate of rise of pressure in said clutches, and when said trolling valve is in said trolling position then pressure fluid flow is blocked to controlled rate of pressure rise means and the latter is manually adjusted by movement of said trolling valve through said range of movement. 